A 


STATE  OP  ILLINOIS 
STATE  HIGHWAY  DEPARTMENT 


wSM 


BULLETIN  NO.  11 


Surface  Oiling  of  Earth 
Roads 


Prepared  by 

B.  H.  PIEPMEIER, 

Maintenance  Engineer,  Illinois  State  Highway  Department 


SPRINGFIELD,  ILLINOIS, 
December  1,  1915 


[Printed  by  authority  of  the  State  of  Ulinote.l 


STATE  OF  ILLINOIS 

STATE  HIGHWAY  DEPARTMENT 


BULLETIN  NO.  11 


Surface  Oiling  of  Earth  Roads 


BY 


B.  H.  PIEPMEIER, 

Maintenance  Engineer,  Illinois  State  Highway  Department 


COMMISSION 

A.  D.  GASH,  President 
S.  E.  BRADT,  Secretary 
JAMES,  P.  WILSON 


WM.  W.  MARR,  Chief  State  Highway  Engineer 


CLIFFORD  OLDER,  Bridge  Engineer 
H.  E.  BILGER,  Road  Engineer 
B.  H.  PIEPMEIER,  Maintenance  Engineer 
F.  L.  ROMAN,  Testing  Engineer 
J.  M.  McCOY,  Chief  Clerk 


SPRINGFIELD,  ILLINOIS 
December  1,  1915 


[Printed  by  authority  of  the  State  of  Illinois.] 


Schnepp  & Barnes,  State  Printers 
SrRINGFIELD,  ILL. 

1915. 


CONTENTS 


PAGE. 

The  Selection  of  Roads  for  Oiling 7 

The  Purpose  of  Oiling 8 

Preparation  of  Earth  Roads 9 

The  Road  Surface  Preparatory  to  Oiling 10 

Applying  Oil  10 

Shipping  and  Handling  Oil 12 

Pumping  Oil  12 

Heating  Oil  14 

Sanding  Oil  Surfaces 16 

Applying  Oil  on  Sandy  Roads 16 

Cost  of  Surface  Oiling 16 

Quality  of  Oil 20 

Oiling  Gravel  and  Macadam  Roads 22 


Digitized  by  the  Internet  Archive 
in  2017  with  funding  from 

University  of  Illinois  Urbana-Champaign  Alternates 


https://archive.org/details/surfaceoilingofeOOpiep 


PREFACE. 


The  State  Highway  Department  has  received  numerous  inquiries 
relative  to  the  advantages  and  methods  of  oiling  earth  roads.  It  seems 
expedient  at  this  time,  therefore,  to  publish  this  treatise  on  surface 
oiling  of  earth  roads  to  aid  in  furnishing  information  that  will  assist 
in  securing  the  best  results  with  this  method. 

As  this  method  of  surface  treatment  is  relatively  new,  there  is 
no  very  definite  information  available  as  to  its  economy.  However, 
an  attempt  has  been  made  in  this  publication  to  give  as  much  infor- 
mation as  is  available.  In  the  majority  of  cases  this  information  will 
answer  the  questions  generally  asked  concerning  such  work. 

The  purpose  of  this  bulletin  is  not  to  cover  in  detail  all  that  might 
be  said  in  regard  to  the  oiling  of  earth  roads,  but  rather  to  give  a 
general  outline  of  the  subject  together  with  suggestions  as  to  the  best 
methods  for  oiling  and  maintaining  earth  roads. 

Wm.  W.  Marr,  Chief  State  Highway  Engineer. 


OILING  OF  EARTH  ROADS. 


The  oiling  of  earth  roads  has  been  practiced  on  a small  scale 
in  a number  of  places  for  the  past  fifteen  years.  California  has  done 
more  of  this  work  than  any  other  state,  primarily  on  account  of  its 
natural  resources  and  climatic  conditions.  It  has  used  a large  amount 
of  oil  and  has  successfully  maintained  many  of  its  roads  by  this  method, 
largely  on  account  of  the  high  grade  oil  that  is  available  at  a very  low 
cost  and  also  on  account  of  the  sandy  condition  of  the  soil,  and  the 
light  winters  that  prevail. 

Illinois  can  never  expect  to  accomplish  the  same  results  in  oiling 
earth  roads  as  has  California.  The  black,  loamy  soil,  the  low  and 
poorly  drained  conditions  of  many  of  the  roads,  together  with  the 
severe  winters  and  springs  make  it  a fallacy  to  expect  anything  like  a 
permanent  road  to  result  from  the  use  of  road  oil. 

It  should  be  kept  in  mind  that  continued  oiling  will  not  make  an 
earth  road  entirely  satisfactory  for  all  localities  or  for  all  conditions 
of  traffic.  The  oiling  of  earth  roads,  like  dragging,  is  a maintenance 
proposition.  The  intelligent  use  of  oil,  like  the  continued  use  of  the 
road  drag,  will  maintain  the  earth  road  so  that  it  will  materially 
improve  the  present  conditions  existing  on  many  of  the  earth  roads  in 
Illinois. 

The  oiling  of  earth  roads  should  not  be  practiced  promiscuously, 
but  used  only  where  the  roads  are  suited  to  such  work.  The  intelli- 
gent use  of  oils  on  many  earth  roads  is  unquestionably  a justifiable 
expense. 

It  is  the  purpose  of  this  publication  to  present  as  many  facts 
concerning  the  use  of  oil  as  it  is  possible  to  secure  at  this  time,  also 
to  describe  what  is  shown  by  experience  to  be  the  best  method  of  pre- 
paring the  road  and  applying  the  oil  together  with  a few  suggestions 
that  may  be  of  some  assistance  to  the  contractor  or  individual  who  has 
such  work  under  consideration. 

The  Selection  of  Roads  for  Oiling. 

Roads  should  not  be  oiled  until  they  have  a permanently  estab- 
lished grade ; that  is,  all  hills  should  be  cut  down,  hollows  filled, 
embankments  widened,  and  all  drainage  structures  established.  Low, 
flat,  undrained  roads  should  not  be  oiled  until  proper  drainage  has 
been  attended  to.  The  oiling  of  a mudhole  will  not  remedy  the 
trouble  but  often  aggravates  it. 

Roads  that  have  a preponderance  of  heavy  hauling  should  not 
be  selected  for  oiling.  The  oiling  tends  to  waterproof  the  road,  but 
it  is  readily  understood  that  continued  heavy  hauling  even  on  per- 
fectly dry  earth  roads  will  eventually  rut  and  dig  them  out  in  pot 
holes.  The  mixture  of  oil  and  earth  lacks  stability  to  meet  all  the 
requirements  of  traffic.  If  something  could  be  mixed  with  the  oil 


8 


Pig.  1.  Oiled  Earth.  Road  15  Feet  Wide  After  First  Treatment  of 
Three-eighths  Gallon  Per  Square  Yard.  Note  the  Road  Was  Well  Graded 
and  Shaped  Before  Oil  Was  Applied.  Such  Work  Insures  The  Best 
Results. 

and  earth  to  give  it  stability  and  aid  it  to  resist  the  wear  of  traffic, 
it  would  more  nearly  meet  all  traffic  conditions. 

On  moderately  traveled  roads  where  there  is  a greater  amount  of 
pleasure  travel,  the  oiled  earth  roads  will  give  better  service. 

The  Purpose  of  Oiling. 

It  should  be  kept  in  mind  that  the  main  purpose  of  oiling  earth 
roads  is  to  suppress  the  dust  and  aid  in  maintaining  a smooth  and 
waterproof  surface.  If  it  is  possible  to  prevent  dust  from  forming, 
the  surface  of  the  road  will  remain  much  smoother  and  there  will 
be  less  mud  form  during  rainy  weather.  By  reducing  the  mud 
nuisance  it  is  possible  to  use  the  road  a larger  portion  of  the  year. 
By  keeping  the  surface  of  an  earth  road  smooth,  the  traffic  is  dis- 
tributed more  uniformly  over  the  road,  thereby  making  it  wear  much 
longer.  The  suppression  of  the  dust  not  only  makes  the  road  wear 
longer,  but  prevents  a portion  of  the  road  from  blowing  into  the 
adjoining  fields,  washing  away,  etc.  The  oil  also  prevents  the  encroach- 
ment of  weeds  and  sod  upon  the  traveled  portion  of  the  highway, 
thus  improving  the  appearance  and  producing  a more  thoroughly  com- 
pacted road. 

The  suppression  of  dust  makes  an  earth  road  more  sanitary  and 
desirable  for  pleasure  traffic.  The  expense  of  oiling  many  roads  is  in 
many  cases  justifiable  from  the  standpoint  of  the  increased  comfort  to 
pleasure  drivers. 


9 


Fig.  2.  Oiled  Earth  Road  Unsatisfactory  on  Account  of  Applying 
Heavy  Oil  on  Top  of  the  Dust  so  That  it  Could  Not  Penetrate  the 
Surface.  The  Oil  and  Dust  Pick  Up  in  Bunches  and  Make  a Very 
Rough  Surface. 

A road  that  is  oiled  systematically  for  a series  of  years  grad- 
ually acquires  an  oil-soaked  crust  which  is  more  or  less  impervious 
to  water.  The  heavy  oil-soaked  crust,  however,  will  rut  if  the  traffic 
is  not  distributed  uniformly  over  the  road  and  it  will  break  through 
during  the  continued  freezing  and  thawing  of  a severe  winter  and 
spring.  This  is  particularly  true  if  the  road  is  used  by  heavy  traffic. 
However,  when  such  roads  rut  and  cut  through,  they  may  be  reshaped 
by  use  of  the  road  drag  at  a very  slight  expense. 

The  purpose  of  the  oiled  earth  road,  therefore,  is  not  to  replace 
what  is  generally  recognized  as  a hard  surfaced  road,  but  to  keep  the 
moderately  traveled  earth  road  in  a suitable  condition  for  ordinary 
traffic  a larger  portion  of  the  year. 

Preparation  of  the  Earth  Road. 

The  mistake  is  often  made  of  attempting  to  improve  a road 
without  first  grading  and  draining  it.  When  a road  is  graded  for 


10 


oiling,  graveling,  or  any  other  form  of  surfacing,  a permanent  grade 
line  should  be  established.  Money  spent  in  properly  grading  an  earth 
road  is  not  wasted,  but  has  practically  its  full  value  when  such  a road 
is  designated  for  later  improvements.  The  great  advantage  of  estab- 
lishing a permanent  grade  and  cross-section  before  the  road  is  oiled  is 
to  utilize  the  oil-soaked  crust  of  earth  as  a foundation  for  later 
improvements,  such  as  gravel,  stone,  brick  or  other  hard  road  surfaces. 
If  oil,  gravel,  or  other  surfacing  material  is  applied  to  an  improperly 
graded  road,  a very  large  portion  of  the  material  will  be  disturbed 
and  practically  wasted  when  later  improvements  are  demanded.  In 
other  words,  any  money  that  is  spent  upon  the  public  highways  should 
be  spent  with  a view  of  further  improvements  that  will  naturally  be 
required  as  traffic  increases. 

The  Road  Surface  Preparatory  to  Oiling. 

As  the  prime  objects  of  oiling  an  earth  road  are  the  suppression 
of  the  dust  and  the  maintaining  of  a smooth  waterproof  surface,  it 
is  very  important  that  the  road  surface  be  oiled  when  it  is  smooth, 
free  from  dust,  and  in  a condition  to  absorb  the  oil. 

Oil  applied  on  dust  will  not  penetrate  the  road  surface,  but  will 
merely  mix  with  the  loose  material  to  make  an  oiled-dust  surface 
that  is  apt  to  fly  readily  and  become  a nuisance.  The  surface  should 
be  perfectly  smooth  and  free  from  low  places  that  will  retain  water. 
If  water  is  allowed  to  stand  upon  an  oiled  earth  surface,  a bad  mud 
hole  will  soon  result.  A moist  subsoil  preparatory  to  oiling  is  not 
serious  though  best  results  may  be  expected  when  the  road  is  reason- 
ably dry  for  about  two  inches  on  the  surface. 

Applying  Oil. 

After  the  road  has  been  prepared  as  heretofore  described,  the 
oil  should  be  applied  at  the  rate  of  one-fourth  to  one-half  gallon  per 
square  yard  of  surface.  If  the  road  has  never  been  oiled,  or  if  more 
than  a season  has  elapsed  since  a previous  oiling,  it  will  be  found 
that  about  one-half  gallon  per  square  yard  will  be  required.  If  the 
road  or  street  has  been  oiled  regularly,  one-fourth  to  one-third  gallon 
per  square  yard  will  usually  be  satisfactory.  It  is  much  better  to  apply 
a small  amount  of  oil  twice  each  season  rather  than  to  put  on  the  full 
quantity  in  one  application.  When  too  much  oil  is  applied,  it  is  not 
only  wasted,  but  is  often  very  disagreeable  to  traffic. 

After  a road  has  been  oiled  for  several  years,  one  light  applica- 
tion each  year  may  be  sufficient,  or  at  least  equal  in  results  to  two  appli- 
cations per  year  on  a new  oiled  road. 

The  time  for  oiling  will  necessarily  vary  considerable  depending 
upon  the  season.  Favorable  times  for  applying  the  oil  will  be  about 
April  and  September. 

The  uniform  distribution  of  the  material  is  one  of  the  essential 
requirements  for  success.  An  ordinary  street  sprinkler  or  a home- 
made device  attached  to  a thresher  tank  wagon  or  similar  tank  may 
be  utilized  for  distributing  the  oil.  An  expert  using  such  equipment 
can  ordinarily  get  the  required  amount  of  oil  on  the  road  rather  uni- 
formly. Much  better  results,  however,  can  be  secured  by  the  use 


11 


Fig.  3.  Oiled  Earth  Road  in  California  Under  Heavy  Traffic.  Note 
That  the  Surface  is  Rather  Badly  Rutted. 


Fig.  4.  Oiled  Earth  Road  in  Spring  of  the  Second  Year.  Surface  is 
Kept  Smooth  by  Means  of  Light  Drag.  The  Continued  Use  of  a Light 
Drag  is  of  Great  Benefit. 


12 


of  some  specially  designed  apparatus  made  for  the  purpose,  such  as 
pressure  distributor  tank  wagons. 

There  are  a number  of  specially  designed  pressure  distributing 
wagons  on  the  market  that  vary  in  price  from  $400  to  $6,000.  The 
horse-drawn  distributors  have  a capacity  of  from  450  to  600  gallons 
and  can  be  purchased  at  from  $400  to  $600.  Such  distributors  are 
usually  equipped  with  some  form  of  heating  device  so  that  hot  oil  may 
be  applied  when  required. 

Some  of  the  auto  distributors  hold  1,000  gallons  and  are  equipped 
with  oil  heaters  for  heating  the  oil  quickly ; also,  special  oil  pumps  for 
filling  the  distributor  and  for  spraying  the  oil  upon  the  road  in  the 
desired  quantities.  Such  trucks  cost  from  $5,000  to  $6,000  complete. 

Shipping  and  Handling  Oil. 

Road  oil  is  usually  shipped  in  8,000  or  10,000  gallon  tank  cars. 
Some  companies  are  able  to  furnish  4,000  and  6,000  gallon  tank  cars, 
but  such  cars  are  very  few  and  usually  hard  to  get.  The  railroad 
tank  cars  are  equipped  with  steam  heating  coils  so  the  material  may 
be  heated  in  the  tank  by  attaching  a steam  pipe  or  hose.  Small  quan- 
tities of  oil  may  be  purchased  in  molasses  barrels,  but  when  delivered 
in  barrels  there  will  be  an  additional  cost  of  two  to  three  cents  per 
gallon.  The  tight  barrels  will  ordinarily  hold  about  50  gallons.  If 
the  barrels  are  handled  with  care  they  can  be  sold  at  50  to  65  cents 
each  when  empty.  Heavy  oil  shipped  in  this  manner  is  usually  very 
difficult  to  remove  from  the  barrels.  In  such  cases  the  barrels  are 
dumped  into  an  open  heating  kettle  and  broken.  After  the  oil  is  warm 
the  staves  and  hoops  may  be  removed  by  a large  hoe  or  rake  and  used 
as  kindling.  The  hot  oil  can  be  pumped  from  the  heating  kettles  to 
the  distributor  and,  while  still  hot,  applied  on  the  road. 

Where  there  is  no  heating  kettle  on  the  job  and  there  are  but  a 
few  barrels  of  heavy  oil  to  apply,  they  may  be  emptied  direct  into 
the  distributing  wagon  by  first  placing  the  barrels  in  a very  warm 
room  or  close  to  a fire  for  several  hours. 

When  there  is  but  a small  quantity  of  oil  desired,  say  3,000  or 
4,000  gallons,  it  is  usually  cheaper  and  much  more  economically 
handled  if  shipped  in  a large  tank  car.  Freight  will  have  to  be  paid 
on  a full  tank  car  of  8,000  or  10,000  gallons,  but  this  will  ordinarily 
be  compensated  for  by  the  saving  in  barrels  and  in  the  economy 
effected  in  handling  the  oil  on  the  job. 

Pumping  Oil. 

There  are  a number  of  special  oil  pumps  on  the  market  that  can 
be  purchased  at  from  $15  to  $30  that  will  readily  pump  hot  or  cold 
oil.  The  rotary  pump  is  the  one  most  commonly  used.  It  may  be 
driven  by  a gasoline  engine  or  a steam  engine,  in  case  the  latter  is 
needed  at  the  tank  car  for  supplying  steam  heat.  A lp2-inch  or 
2-inch  rotary  pump  will  fill  a 600-gallon  distributor  in  from  ten  to 
fifteen  minutes. 

The  ordinary  water  tank  pump  may  be  used  for  pumping  cold 
oil.  A 2-inch  suction  tank  pump  will  fill  a 600-gallon  tank  in  30  to 
40  minutes.  Such  pumps  cannot  be  used  for  hot  oil,  as  it  will  soon 
burn  out  the  valves. 


13 


Fig.  5.  Proper  Drainage  is  Important  on  All  Earth  Roads  Before 
Oiling.  There  Are  Many  Flat,  Seepy  Places  That  Should  be  Drained 
by  Tiling.  A Line  of  Tile  on  Some  Sections  of  Road  Will  Relieve  the 
Underground  Water  Pressure  and  Tend  to  Prevent  the  Oil  Soaked 
Earth  Crust  From  Rutting. 


Fig.  6.  Grading  and  Compacting  on  Earth  Road  Prior  to  Oiling.  It 
is  Important  That  an  Earth  Road  Have  a Proper  Grade  and  be  Thor- 
oughly Compacted  Before  the  Oil  is  applied. 


14 


All  of  the  above  named  pumps  work  best  attached  to  the  bot- 
tom of  the  railroad  tank  car  by  means  of  a hose  or  pipe.  However, 
it  is  well  to  eliminate  hose  connections  as  much  as  possible  as  some 
oils  and  tars  eat  them  out  very  rapidly. 

A 3-inch  or  4-inch  lift  pump  may  be  used  to  an  advantage  in 
pumping  oils.  Such  pumps  are  set  in  the  tank  car  at  the  top  and  one 
man  will  readily  pump  a 600-gallon  tank  in  20  minutes.  This  kind 
of  pump  can  be  purchased  for  $20  to  $25.  It  has  many  advantages 
as  there  is  no  mechanical  power  needed  nor  any  pipe  or  hose  connec- 
tions. 

After  the  pump  is  connected  at  the  bottom  of  the  tank  car  and 
everything  is  ready  to  receive  the  oil,  the  cap  on  the  dome  of  the 
car  should  be  unscrewed  and  the  discharge  valve  opened  from  the 
inside.  This  valve  has  a stem  projecting  up  to  the  dome.  It  is  well 
to  have  a cut-off  valve  in  the  hose  or  pipe  connection  at  the  bottom 
so  the  tank  car  valve  may  be  left  open  during  the  day  that  oil  is 
being  used. 

If  there  is  an  elevated  siding  or  switch  eight  or  ten  feet  high 
at  the  station,  the  tank  can  be  spotted  thereon  and  the  oil  allowed 
to  flow  by  gravity  into  the  distributing  wagon  from  the  tap  in  the 
bottom  of  the  tank  car. 


Heating  Oil. 

Where  oil  must  be  heated  before  being  applied,  it  is  often  con- 
venient to  spot  the  car  on  a spur  near  some  steam  plant,  such  as  a mill, 
creamery,  or  electric  light  plant.  Where  such  arrangements  can  be 
made,  a ^-inch  or  1-inch  steam  pipe  line  may  be  connected  from 
the  plant  to  the  tank  car.  If  no  steam  plant  is  accessible,  an  ordinary 
steam  tractor  or  roller  can  be  connected  with  the  tank  car.  Where 
a steam  connection  is  made  for  supplying  the  heat,  from  12  to  24 
hours  are  required  to  bring  the  oil  up  to  150  to  175  degrees  F.  which 
is  about  the  maximum  temperature  that  can  be  reached  with  the 
steam  heat.  This  temperature  will  permit  the  oil  to  be  pumped 
readily.  Its  temperature  may  then  be  increased  the  desired  amount 
in  the  distributor. 

The  steam  connection  with  the  tank  car  is  made  at  one  of  the 
2-inch  pipes  that  project  beneath  the  tank,  the  other  2-inch  pipe  that 
projects  should  be  supplied  with  a valve  so  the  amount  of  steam  passing 
through  the  coils  may  be  regulated. 

It  is  advisable  to  have  a thermometer  on  the  job  so  that  the 
temperature  of  the  hot  oil  may  be  tested  from  time  to  time. 

Some  road  oils  have  a very  low  flash  point  and  extreme  care 
should  be  taken  to  prevent  any  oil  from  coming  into  contact  with  a 
flame.  An  analysis  of  an  oil  always  shows  the  flash  point  so  it  is  well 
to  keep  the  temperature  somewhat  lower  to  prevent  burning  and  to 
be  on  the  safe  side. 

The  presence  of  a slight  amount  of  water  in  heating  oil  will 
cause  the  oil  to  foam  and  give  a great  deal  of  trouble.  Where  the 
oil  tends  to  foam,  it  should  be  heated  very  slowly.  In  such  cases  every 
precaution  should  be  taken  to  prevent  accidents. 


15 


Fig.  7.  A Well  Graded  Earth  Road  But  Badly  Cut  Up  at  Time 
Picture  Was  Taken.  It  Should  be  Carefully  Dragged  and  Compacted 
Under  Heavy  Roller  Before  Oiling.  A Uniformly  Compacted  Surface 
Will  Show  the  Best  Results  After  Oiling. 


Fig.  8.  Roads  Graded  in  This  Way  Are  Unsatisfactory  For  Oiling. 
It  is  Almost  Impossible  to  Thoroughly  Compact  the  Center  of  the  Road 
on  Account  of  the  Sod  and  Humus  that  Has  Been  Carelessly  Dragged 
to  the  Center. 


16 


Sanding  Oil  Surfaces. 

Better  results  can  be  secured  from  sanding  the  road  slightly 
after  either  hot  or  cold  oil  has  been  applied.  Clean  hard  sand  is 
much  better  on  a road  surface  than  dust  or  the  sweepings  from  the 
road.  A hot  oil  application  should  be  followed  with  a light  dressing 
of  sand,  or  the  traffic  will  likely  pick  up  the  oil  and  make  the  sur- 
face of  the  road  very  uneven.  Sand  may  be  applied  at  the  rate  of 
one  cubic  yard  to  each  100-  to  150  square  yards  of  road  surface. 
It  may  be  applied  by  shovels  from  a wagon  or  from  a special  apparatus 
for  distributing  the  sand. 

The  application  of  sand  gives  an  oiled  earth  surface  more  stabil- 
ity. The  sand  retains  the  oil,  assists  in  preventing  wear,  and  aids 
in  keeping  down  the  dust.  The  light  application  of  sand  is  a justifiable 
expense. on  a majority  of  oiled  earth  roads. 

Oiling  Sandy  Roads. 

There  are  many  sections  of  roads  in  Illinois  that  are  very  sandy 
and  will  have  to  be  handled  differently  than  the  ordinary  earth  road. 
Where  it  is  possible  to  mix  clay  or  loam  with  the  top  four  or  five 
inches  of  »and  before  oiling,  much  better  results  may  be  expected. 
A suitable  clay  or  loam  can  usually  be  secured  at  a reasonable  distance 
from  the  sandy  section.  Where  possible,  the  sand  and  clay  should 
be  thoroughly  mixed  and  allowed  to  compact  under  traffic  before 
the  oil  is  applied.  The  sand-clay  road  will  permit  a slightly  heavier 
oil  than  the  ordinary  earth  road. 

If  there  is  no  clay  or  loam  within  reasonable  distance  of  the  sand 
road,  it  may  be  materially  improved  by  mixing  a heavy  oil  (70  to  90 
per  cent  asphaltic  product)  with  four  or  five  inches  of  the  top  layer 
of  sand.  This  can  best  be  done  by  applying  about  three-fourths 
gallon  of  oil  and  then  covering  it  with  about  one  inch  of  the  sandy 
soil  from  the  road  side,  then  applying  about  one-half  gallon  of  oil  and 
another  layer  of  sand.  By  building  up  successive  layers  of  oil  and 
sand,  it  is  possible  to  get  from  one  and  one-half  to  two  gallons  of  oil 
per  square  yard  of  surface.  This  amount  of  oil  mixed  with  four 
or  five  inches  of  the  sandy  soil  will  form  a solid  oil  and  sand  crust 
that  will  hold  up  light  traffic.  The  cost  of  such  applications  will 
vary  from  $800  to  $1,500  per  mile  of  road  fifteen  feet  wide. 

The  cost  of  applying  a four  or  five  inch  layer  of  clay  or  loam  that 
may  be  secured  within  one  mile  of  the  road,  and  mixing  it  with  the 
sand,  will  be  about  the  same.  It  is  generally  recognized  that  the 
mixture  of  sand  and  clay  is  more  serviceable  that  the  mixture  of 
oil  and  sand. 

The  Cost  of  Surface  Oiling. 

The  cost  of  preparing  a public  road  for  an  oil  treatment  may  vary 
from  $100  to  $2,000  per  mile.  However  the  grading  and  preparation 
of  an  earth  road  should  not  be  charged  against  the  cost  of  oiling.  The 
oiling  or  dragging  of  an  earth  road  is  a maintenance  proposition  and 
should  be  estimated  separately  from  the  building  or  preparing  of  the 
road.  The  road  should  be  kept  well  shaped  regardless  of  whether  it  is 


17 


Fig.  9.  Removing  Dust  From  the  Surface  of  a Road  by  Means  of 
a Street  Sweeper  Before  Applying  Oil.  The  Best  Results  Are  Secured 
From  Oiling  Earth  Roads  That  Are  Free  From  Dust. 


Fig.  10.  Oiled  Earth  Road  After  Two  Weeks  of  Summer  Rains. 
Surface  in  Excellent  Condition.  Note  Uniform  Grade  and  Crown  of 

Road. 


18 


to  be  oiled  or  not.  However,  some  cleaning  is  almost  always  necessary 
prior  to  the  first  application  of  oil,  and  this  cost  will  vary  from 
$25  to  $50  per  mile  of  road. 

Road  oil  can  be  purchased  for  from  three  to  seven  cents  per  gallon, 
depending  upon  the  quality.  It  may  be  applied  on  the  surface  of  the 
road  at  the  rate  of  one-fourth  to  one-half  gallon  per  square  yard. 
So  the  cost  of  oil  alone  may  vary  from  $75  to  $275  per  mile  of  road 
15  feet  wide,  depending  upon  the  quality  and  quantity  of  oil  applied. 

The  cost  of  applying  the  oil  will  vary  depending  upon  the  length 
of  haul  and  the  kind  of  equipment  used.  This  cost  may  be  estimated 
at  from  $50  to  $150  per  mile  of  road  15  feet  wide. 

The  above  figures  show  the  cost  of  oiling  to  vary  from  $150  to 
$475  per  mile  of  road.  With  average  conditions  and  with  a medium 
priced  oil,  the  average  cost  of  oiling  alone  per  application  may  be 
from  $200  to  $250  per  mile  of  road  15  feet  wide.  It  must  be  under- 
stood that  these  costs  are  based  on  the  conditions  prevailing  during  the 
season  of  1915. 

It  is  understood  that  the  above  figures  are  only  an  approximate 
estimate.  A complete  record  of  the  cost  of  oiling,  together  with  the 
quality  and  quantity  of  oil  used  each  year  over  a period  of  years  is 
not  available.  The  above  figures,  however,  are  based  on  the  best  infor- 
mation available  in  this  and  other  similar  states. 

It  is  predicted  by  same  enthusiastic  users  that  a road  will  not 
require  oiling  after  it  has  been  oiled  for  two  or  three  years  and  the 
surface  has  become  thoroughly  saturated  with  the  oil.  The  writer 
has  visited  some  twenty  different  towns  that  have  oiled  their  streets 
for  a period  of  more  than  five  years  and  the  present  condition  of  such 
streets  indicates  that  the  oiling  will  have  to  be  repeated  each  year 
indefinitely  to  secure  the  desired  results.  The  quality  or  quantity 
of  oil  used  in  the  twenty  towns  referred  to  is  not  known.  It  may 
be  that  if  a high  grade  of  asphaltic  oil  is  used  that  some  annual  appli- 
cations may  be  omitted  after  a few  years  of  treatment.  With  the 
best  oil,  however,  it  is  hardly  expected  that  more  than  one  year  could 
elapse  without  some  attention. 

Some  experiments  have  been  made  along  the  line  of  thoroughly 
saturating  the  top  six  inches  of  earth  and  then  compacting  it  with  a 
petrolithic  roller.  The  saturating  of  the  earth  with  the  first  appli- 
cation of  two  and  one-half  to  three  gallons  of  oil  was  intended  to 
resemble  somewhat  the  continual  oiling  of  the  surface  over  a period 
of  four  or  five  years.  The  experiments  referred  to  were  made  in 
1908  and  1909  on  three  different  sections  of  road  of  one-half  to  three- 
fourths  of  a mile  in  length.  Two  of  the  sections  were  considered  fail- 
ures and  were  within  three  years  covered  with  a more  desirable  wearing 
surface.  The  third  section  still  remains;  however,  it  shows  very  few 
signs  of  having  such  a treatment.  This  section  seems  to  rut  in  the 
winter  and  spring  almost  as  badly  as  the  other  portion  of  the  road; 
in  midsummer  the  surface  of  the  road  pulverizes  and  forms  a dust 
that  flies  almost  the  same  as  dust  from  other  portions  of  the  road. 

In  view  of  all  the  information  that  is  available  on  oiled  earth 
roads,  indications  are  that  the  treatments  must  be  made  each  year  or 
at  least  every  other  year  to  get  the  desired  results.  On  this  basis, 


19 


Fig.  11.  Pressure  Distributor  For  Applying  Hot  or  Cold  Oil.  Heat 
Supplied  by  Coal  Furnace  Under  Tank.  Equipment  Owned  by  The 
State  Highway  Department. 


Fig.  12.  Pressure  Distributor  For  Applying  Cold  Oil. 


20 


$150  to  $200  per  year  for  five  to  ten  years  may  be  a basis  for  estimat- 
ing the  cost  of  surface  oiling. 

Quality  of  Oil. 

On  practically  all  work  that  has  been  done  in  the  past,  a light 
oil  with  a paraffin  or  semi-asphaltic  base  has  been  used.  There  is 
very  little  information  available  on  the  use  of  the  higher  grades  of 
asphaltic  oil  on  earth  roads.  It  is  predicted  by  our  best  authori- 
ties that  the  use  of  the  higher  grade  asphaltic  oils  will  prove  to  be 
more  satisfactory  and  more  economical  in  the  end  than  the  use  of 
inferior  products. 

It  seems  to  be  the  unanimous  opinion  of  all  extensive  users 

of  road  oils  that  the  semi-asphaltic  products  are  far  superior  to  the 

paraffin  oils. 

From  the  information  that  we  have,  therefore,  it  seems  essential 
that  careful  analysis  be  made  of  all  road  oils  before  using  and  that 
preference  be  given  to  the  natural  and  semi-asphaltic  products  over 
the  paraffin  oils. 

The  best  products  are  secured  only  by  purchasing  the  material 
under  carefully  drawn  specifications  and  using  the  same  under  the 
approval  of  a competent  chemist. 

The  amount  of  asphalt  or  residue  that  a product  may  contain 

does  not  classify  it  as  a suitable  material  for  the  road  under  con- 

sideration. For  instance,  a thick  heavy  material  with  40  per  cent 
asphalt  or  residue  will  not  give  the  same  results  as  a light  thin 
product  of  the  same  asphaltic  content. 

The  purpose  of  oiling  an  earth  road  is  the  suppression  of  dust 
and  the  waterproofing  of  the  surface.  It  is  evident,  therefore,  that 
the  best  results  may  be  secured  during  the  first  application,  by 
applying  either  a cold  oil  or  at  least  a very. thin  product  that  will 
penetrate  the  surface  of  the  road  several  inches  and  at  the  same 
time  contain  as  many  binding  elements  as  possible  so  as  to  seal  all 
pores  in  the  earth,  making  it  waterproof  and  at  the  same  time  adding 
some  binding  qualities  that  may  assist  the  bond  of  the  soil  itself. 
A suitable  product,  as  is  commonly  expressed,  may  very  from  30  to  60 
per  cent  in  asphalt.  After  the  surface  of  the  road  has  been  thoroughly 
saturated,  a hot  oil  or  a slightly  heavier  product  may  be  used. 

If  the  heavier  oils  are  used  for  the  first  application  they  will 
not  readily  penetrate  the  surface  of  the  road  and  will  consequently 
form  a mat  on  top.  The  forming  of  the  mat  before  the  surface  of 
the  road  is  more  or  less  waterproof  may  be  a serious  fault  as  moisture 
will  accumulate  beneath  the  mat  and  the  road  will  be  much  slower 
in  drying  out  than  it  would  had  the  oil  not  been  applied.  The  mat 
surface  with  a soft  subsoil  will  rut  more  readily,  besides  breaking 
and  scaling  off  in  large  pieces,  making  the  road  surface  rough  and 
undesirable. 

The  paraffin  oils  are  ordinarily  thin  and  light,  yet  they  do  not 
contain  sufficient  binding  elements  to  seal  and  hold  the  surface  of 
a road.  Such  oils  after  being  in  use  a short  while  apparently  have 
very  little  value  as  they  permit  the  surface  of  the  road  to  grind 
up  into  a light  oil-mixed  powder  which  makes  a slick,  slimy  mud 


21 


Fig.  13.  Pressure  Distributor  For  Applying  Hot  Oil.  Heat  Supplied 
by  Oil  Burners. 


Fig.  14.  Pressure  Distributor  For  Applying  Cold  Oil.  The  Spraying 
Attachment  Can  be  Attached  to  an  Ordinary  Tank  Wagon  as  Shown 
in  the  Cut. 


22 


when  wet,  and  which  when  dry,  flies  almost  as  readily  as  the  ordinary 
dust.  The  oiled  dust  becomes  very  disagreeable  when  it  flies.  It 
dulls  the  glossy  finish  on  vehicles,  makes  the  eyes  burn  and  almost 
ruins  clothing  and  household  furnishings.  A number  have  remarked 
that  a poorly  oiled  earth  road  is  much  worse  than  no  oiled  road. 

Oiling  Gravel  and  Macadam  Roads. 

Gravel  and  macadam  roads  that  are  in  good  shape  may  be  eco- 
nomically maintained  by  applying  a surface  treatment  of  oil  or  tar. 
Where  gravel  or  macadam  roads  are  subjected  to  a large  amount  of 
motor  traffic,  they  soon  become  very  rough  and  begin  to  ravel.  This 
is  largely  due  to  the  fast  motor  traffic  that  whips  out  the  bonding 
material  that  holds  the  stones  or  pebbles  in  place  on  the  surface  of 
the  road.  To  maintain  such  roads,  it  seems  necessary  that  some  bitu- 
minous products  be  applied  occasionally  to  the  surface  of  the  road  to 
retain  the  bonding  material  and  to  prevent  rapid  deterioration  of  the 
road. 

Experience  shows  that  more  care  should  be  taken  in  the  prepara- 
tion of  the  road  surface  and  in  the  selection  of  the  quality  of  bitu- 
minous products  than  in  the  oiling  of  earth  roads.  It  is  not  the  pur- 
pose of  this  bulletin  to  deal  with  the  maintenance  of  gravel  or 
macadam  roads ; more  complete  information  may  be  had  upon  this 
subject  together  with  complete  specifications  for  oiling  earth,  gravel 
or  macadam  roads,  by  requesting  Bulletin  No.  6,  Dust  Prevention, 
from  the  State  Highway  Department. 


23 


Fig.  15.  Six  Hundred  Gallon  Pressure  Distributor  For  Cold  Oil. 
Pressure  Secured  From  Rotary  Pump  Driven  From  Rear  Wheel. 


Fig.  16.  Pressure  Distributor  Applying  Cold  Oil.  Poor  Results  May 
be  Expected  From  Such  Uneven  Distribution  of  the  Oil.  Note  That 
Only  About  One-half  of  the  Nozzles  Are  Working  Properly. 


24 


Fig.  17.  Applying  Heavy  Asphaltic  Material  at  the  Rate  of  One- 
fourth  Gallon  Per  Square  Yard  of  Surface.  Material  is  Heated  by 
Kerosene  Burners  Beneath  the  Tank.  Note  Uniform  Distribution  of 
the  Asphalt. 


Fig.  18.  Applying  Oil  From  a Gravity  Distributor.  With  Such 
Equipment  it  is  Almost  Impossible  to  Distribute  the  Oil  Uniformly. 
A Uniform  Distribution  of  the  Oil  Insures  the  Best  Results. 


25 


Fig.  19.  One  Thousand  Gallon  Auto  Pressure  Oil  Distributor  For 
Applying  Hot  or  Cold  Oil.  Such  Equipment  Has  Been  Used  in  Dis- 
tributing Oil  25  Miles  From  the  Supply. 


Fig.  20.  Eight  Hundred  Gallon  Auto  Pressure  Oil  Distributor  For 
Applying  Cold  Oil. 


26 


Fig.  21.  Unloading  Hot  Oil  From  Railroad  Tank  Car  Into  Dis- 
tributor by  Means  of  a Rotary  Pump  Attached  to  the  Tap  in  the  Bot- 
tom of  the  Car.  Tank  Car  Heated  With  Steam  From  Adjacent  Ice 
Plant. 


Fig.  22.  Sandy  Road  That  May  be  Found  in  a Few  Places  in 
Illinois.  Such  Roads  May  be  Improved  by  Applying  Four  or  Five 
Inches  of  Clay  and  Thoroughly  Mixing  it  With  the  Sand,  or  in  Mixing 
Heavy  Oil  With  the  Top  Four  or  Five  Inches  of  the  Sandy  Surface. 


27 


Fig.  23.  Oiled  Sand  Road  in  California.  Surface  Not  Entirely 
Satisfactory  on  Account  of  the  Greasy  Oil  Used. 


Fig.  24.  Oiled  Earth  Road  After  Thoroughly  Mixing  Oil  With  Top 
Five  Inches  of  Earth.  Three  Gallons  of  Oil  Used  Per  Square  Yard 
of  Surface.  Condition  Not  Entirely  Satisfactory  as  it  Breaks  Up  in 
Winter  and  Spring.  More  Economic  Results  May  Be  Secured  From 
Continued  Surface  Oiling. 


28 


Fig.  25.  Sand  Spreader  Sprinkling  Coarse  Sand  Over  Freshly  Oiled 
Surface.  The  Spreader  Holds  About  One  Ton  of  Coarse  Sand  or  Stone 
Chips  and  Drills  it  Uniformly  Over  the  Oiled  Surface.  The  Spreader 
May  be  Loaded  From  Piles  Alongside  of  the  Road  or  Direct  From 
Wagons.  On  Light  Oils  the  Spreader  May  be  Hitched  to  the  Sand 
Wagons  and  Materials  Shoveled  Into  the  Spreader  Direct. 


Fig.  26.  Macadam  Road  Maintained  Under  Heavy  Traffic  by  Means 
of  Annual  Treatments  of  a Bituminous  Material  and  Coarse  Sand. 


